TrailerWiring

Normally there is a bundle of wires in the jack compartment at the right rear corner of the van. You will have to supply the connector that matches the trailer that you want to tow. For most lightweight or rental trailers that use surge brakes this is a simple 4pin flat connector like https://amzn.to/3dWXNmC which includes some extra wire for routing. 

Once you move up to electronic brakes or a trailer equipped with reverse lights or has aux power requirements, then you require more pins.  That is where the 5,6,7 and 8 pin connectors come into play. https://en.wikipedia.org/wiki/Trailer_connectors_in_North_America

Also, see the towing and trailer hitch page here: Towing/Trailer Hitch 

Vehicle side wiring harness colors are usually as follows but you should double check your owners/users/repair manual or use a meter to confirm.

• Brown: Rear running lights

• Yellow: Left stop and turn

• Dark Green: Right stop and turn

• White (Heavy Gage): Ground

• Light Green: Back-up lamps

• White (Light Gage): Center High-Mounted Stoplamp

• Blue: Auxiliary circuit (8wire harness only) usually needs to be connected to a brake controller, up by the convenience center, drivers left foot(sometimes taped to the battery feed).

• Orange: Fused auxiliary (8wire harness only) sometimes already connected/fused(30amp upfitter-batt)

Every trailer wiring connection type and trailer has it's own quirks.  4 through 8 pin connectors, even sometimes the connectors are the same but wired differently depending on it's purpose and trailer usage.

4-Pin Flat

The basic 4pin flat connector is the simplest, most common and standardized connection for light duty trailers, used to power the lights on the trailer and nothing else.  Example 4-pin flat connector: vehicle side https://amzn.to/3uZSo54

• • White - Ground wire

  • Brown - Tail/running lights wire

  • Green - Right turn and brake lights wire

  • Yellow - Left turn and brake lights wire

5-Pin Flat and 5-pin round

The 5pin flat connector is the same as the 4pin with an added circuit for electric trailer brakes or aux power.  Make sure the trailer and vehicle wiring matches as there are different combinations.  When in doubt, check with a meter.  Example 5-pin flat connector: shows both vehicle and trailer side https://amzn.to/3jau76Y  There is also a less common(these days) 5-pin round connector type.

• • Blue - Electric trailer brakes or aux power wire

  • White - Ground wire

  • Brown - Tail/running lights wire

  • Green - Right turn and brake lights wire

  • Yellow - Left turn and brake lights wire

6-Pin Round

The 6pin round connector has the same pins as the 4pin flat for the running/brake/turn lights, but has 2 extra circuits for electric trailer brakes/aux power/reverse lights.  Make sure the trailer and vehicle wiring matches as there are multiple possible combinations.  When in doubt, check with a meter.  Trailer connector example https://amzn.to/37nNJC1

7-Way Round RV

The 7-way Round RV 7-blade round connector adds 1 more circuit over the 6pin, usually to add aux power or reverse lights.  Make sure the trailer and vehicle wiring matches as there are multiple possible combinations.  When in doubt, check with a meter.  This would be the standard connector type I would install in our vans if you ever plan on using a camping trailer or tow dolly/trailer with electric brakes, it provides the most versatility and can be adapted to any other type of connector.  This is what the trailer connector looks like https://amzn.to/3r7dYDz  The combination ones that have the 7-blade round RV and the flat 4 connection are ideal as it covers the most common setups without needing adapters.  Example adapter:  https://amzn.to/3uSh8MC

There is also a less common 7-pin round connector as well, and sometimes when shopping you will see the 7-blade called the 7-pin, so be careful and pay attention to what you are purchasing.

Other connectors and converters

Some setups require brake light converters or use alternative connectors.  This is an issue on vehicles or trailers that separate the rear brake and turn signals instead of using the same bulb for both.  On our stock vans in North America, we don't require converters and usually use the standard connectors above so I will not currently be covering all of the other possible setups/connectors here.  If someone really needs this information, see the contact page and get a hold of me and I will help you as best as possible.

Brake Controllers

Trailer brakes are often required by law above a certain weight and are recommended for any trailer over 1,000lbs.  Rentals often use hydraulic surge brakes, but others are more commonly set up with electric trailer brakes that require a controller installed in the vehicle.  Adding a vehicle side brake controller for electric brakes on our vans is generally pretty easy considering that for many, most the wiring is already in place.  The wiring that needs to be connected is as follows(follow the owners/users/installation manuals)

• Ground(usually WHITE on controller)

• Brake switch cold side connection(usually RED on controller) that has 12v to it only when the brake pedal is pressed

• Brake controller output(usually BLUE) connected to the blunt cut dark blue wire near the convenience center(factory wire that goes back to trailer wiring harness bundle in the jack storage area)

• Battery positive protected by a properly sized self resetting circuit breaker, usually 20amp or 30amp(usually BLACK on controller).  Don't use a fuse, fusible link, or a manual reset circuit breaker for the power supply to the electric brake controller.  Your specific brake controller should have the power supply requirements in the owner/installation manual or contact the MFG.